Navegando por Autor "Carraro, Dirce Maria"

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Assessment of somatic mutations in urine and plasma of Wilms tumor patients
(Wiley, 2020-06) Miguez, Ana Carolina Kerekes; Barros, Bruna D. de Figueiredo; Souza, Jorge Estefano Santana de; Costa, Cecília Maria L. da; Cunha, Isabela Werneck; Barbosa, Paula Nicole Vieira P.; Apezzato, Maria Lúcia P.; Souza, Sandro José de; Carraro, Dirce Maria
Tumor DNA has been detected in body fluids of cancer patients. Somatic tumor mutations are being used as biomarkers in body fluids to monitor chemotherapy response as a minimally invasive tool. In this study, we evaluated the potential of tracking somatic mutations in free DNA of plasma and urine collected from Wilms tumor (WT) patients for monitoring treatment response. Wilms tumor is a pediatric renal tumor resulting from cell differentiation errors during nephrogenesis. Its mutational repertoire is not completely defined. Thus, for identifying somatic mutations from tumor tissue DNA, we screened matched tumor/leukocyte DNAs using either a panel containing 16 WT‐associated genes or whole‐exome sequencing (WES). The identified somatic tumor mutations were tracked in urine and plasma DNA collected before, during and after treatment. At least one somatic mutation was identified in five out of six WT tissue samples analyzed. Somatic mutations were detected in body fluids before treatment in all five patients (three patients in urine, three in plasma, and one in both body fluids). In all patients, a decrease of the variant allele fraction of somatic mutations was observed in body fluids during neoadjuvant chemotherapy. Interestingly, the persistence of somatic mutations in body fluids was in accordance with clinical parameters. For one patient who progressed to death, it persisted in high levels in serial body fluid samples during treatment. For three patients without disease progression, somatic mutations were not consistently detected in samples throughout monitoring. For one patient with bilateral disease, a somatic mutation was detected at low levels with no support of clinical manifestation. Our results demonstrated the potential of tracking somatic mutations in urine and plasma DNA as a minimally invasive tool for monitoring WT patients. Additional investigation is needed to check the clinical value of insistent somatic mutations in body fluids.
Bioinformática aplicada ao desenvolvimento de estratégias de prognóstico e tratamento do câncer: estudos na prospecção de alvos terapêuticos, antígenos tumorais e na dinâmica de resposta a drogas
(2018-11-01) Faustino, André Luís Fonseca; Souza, Sandro José de; ; ; Souza, Gustavo Antonio de; ; Lima, Lucymara Fassarella Agnez; ; Carraro, Dirce Maria; ; Balbino, Valdir;
Essencialmente, a pesquisa do câncer é um campo que envolve vários ramos, abrangendo a compreensão da biologia do câncer, design de drogas e desenvolvimento terapêutico. De maneira geral, a pesquisa contra o câncer está concentrada no diagnóstico, prognóstico, tratamento e, finalmente, na cura do paciente. Nesse contexto, a bioinformática do câncer surge como um poderoso recurso, integrando dados públicos e, consequentemente, permitindo o avanço de aplicações clínicas. Têm-se como exemplo, o desenvolvimento de abordagens para tratamento, a descoberta de novas drogas e também, recentemente, de estratégias imunoterapêuticas. Neste trabalho, apresenta-se abordagens distintas para compreender a biologia do câncer com foco no seu tratamento e, principalmente, na predição do prognóstico. Cada capítulo mostra diferentes aplicações clínicas como, a previsão de resultados de sobrevida, oportunidades para novos tratamentos imunológicos e resistência a drogas. Nos capítulos iniciais são apresentados catálogos extensivos de genes associados a: i) marcadores de superfície de celular e ii) antígenos de câncer/testículo (CTAs). Em particular, foi demonstrado o efeito de assinaturas gênicas compostas por essas categorias, na predição do status de prognóstico em pacientes com câncer. Em um segundo momento, foi discutido o desenvolvimento de novas estratégias de imunoterapia baseadas em vacinas, combinando múltiplos CTAs. Particularmente, discute-se como as assinaturas de CTAs compostas por HEATR9, INSL3, GTSF1L e HSF5 melhoram o status de prognóstico em pacientes com melanoma. Por último, apresentamos uma metodologia com foco na regulação póstranscricional, a qual integra informação genotípica, dados de expressão e concentração de drogas para avaliar a resistência/sensibilidade do tratamento, utilizando dados de linhagem celular e de pacientes. Como conclusão, foram apresentadas três abordagens independentes para melhorar o tratamento do câncer, que podem ser usadas combinando ou não, os marcadores de prognóstico da superfície celular, o preditor de resposta a drogas e as vacinas contra o câncer. Ainda, como outros produtos importantes, são mencionados dois artigos publicados em períodos internacionais, bem como, uma patente em andamento.
Family-based whole-exome sequencing identifies rare variants potentially related to cutaneous melanoma predisposition in Brazilian melanoma-prone families
(Public Library of Science (PLoS), 2022-01-27) Fidalgo, Felipe; Torrezan, Giovana Tardin; Sá, Bianca Costa Soares de; Barros, Bruna Durães de Figueiredo; Moredo, Luciana Facure; Valieris, Renan; Souza, Sandro José de; Duprat, João Pereira; Krepischi, Ana Cristina Victorino; Carraro, Dirce Maria
Genetic predisposition accounts for nearly 10% of all melanoma cases and has been associated with a dozen moderate- to high-penetrance genes, including CDKN2A, CDK4, POT1 and BAP1. However, in most melanoma-prone families, the genetic etiology of cancer predisposition remains undetermined. The goal of this study was to identify rare genomic variants associated with cutaneous melanoma susceptibility in melanoma-prone families. Whole-exome sequencing was performed in 2 affected individuals of 5 melanoma-prone families negative for mutations in CDKN2A and CDK4, the major cutaneous melanoma risk genes. A total of 288 rare coding variants shared by the affected relatives of each family were identified, including 7 loss-of-function variants. By performing in silico analyses of gene function, biological pathways, and variant pathogenicity prediction, we underscored the putative role of several genes for melanoma risk, including previously described genes such as MYO7A and WRN, as well as new putative candidates, such as SERPINB4, HRNR, and NOP10. In conclusion, our data revealed rare germline variants in melanoma-prone families contributing with a novel set of potential candidate genes to be further investigated in future studies
A genomic case study of desmoplastic small round cell tumor: comprehensive analysis reveals insights into potential therapeutic targets and development of a monitoring tool for a rare and aggressive disease
(2016) Ferreira, Elisa Napolitano; Barros, Bruna Durães Figueiredo; Souza, Jorge Estefano de; Almeida, Renan Valieris; Torrezan, Giovana Tardin; Garcia, Sheila; Krepischi, Ana Cristina Victorino; Mello, Celso Abdon Lopes de; Cunha, Isabela Werneck da; Pinto, Clóvis Antonio Lopes; Soares, Fernando Augusto; Dias-Neto, Emmanuel; Lopes, Ademar; Souza, Sandro José de; Carraro, Dirce Maria
Background: Genome-wide profiling of rare tumors is crucial for improvement of diagnosis, treatment, and, consequently, achieving better outcomes. Desmoplastic small round cell tumor (DSRCT) is a rare type of sarcoma arising from mesenchymal cells of abdominal peritoneum that usually develops in male adolescents and young adults. A specific translocation, t(11;22)(p13;q12), resulting in EWS and WT1 gene fusion is the only recurrent molecular hallmark and no other genetic factor has been associated to this aggressive tumor. Here, we present a comprehensive genomic profiling of one DSRCT affecting a 26-year-old male, who achieved an excellent outcome. Methods: We investigated somatic and germline variants through whole-exome sequencing using a family based approach and, by array CGH, we explored the occurrence of genomic imbalances. Additionally, we performed mate-paired whole-genome sequencing for defining the specific breakpoint of the EWS-WT1 translocation, allowing us to develop a personalized tumor marker for monitoring the patient by liquid biopsy. Results: We identified genetic variants leading to protein alterations including 12 somatic and 14 germline events (11 germline compound heterozygous mutations and 3 rare homozygous polymorphisms) affecting genes predominantly involved in mesenchymal cell differentiation pathways. Regarding copy number alterations (CNA) few events were detected, mainly restricted to gains in chromosomes 5 and 18 and losses at 11p, 13q, and 22q. The deletions at 11p and 22q indicated the presence of the classic translocation, t(11;22)(p13;q12). In addition, the mapping of the specific genomic breakpoint of the EWS-WT1 gene fusion allowed the design of a personalized biomarker for assessing circulating tumor DNA (ctDNA) in plasma during patient follow-up. This biomarker has been used in four post-treatment blood samples, 3 years after surgery, and no trace of EWS-WT1 gene fusion was detected, in accordance with imaging tests showing no evidence of disease and with the good general health status of the patient. Conclusions: Overall, our findings revealed genes with potential to be associated with risk assessment and tumorigenesis of this rare type of sarcoma. Additionally, we established a liquid biopsy approach for monitoring patient follow-up based on genomic information that can be similarly adopted for patients diagnosed with a rare tumor.
Influence of BRCA1 germline mutations in the somatic mutational burden of triple-negative breast cancer
(2019-08) Ferreira, Elisa Napolitano; Brianese, Rafael Canfield; Almeida, Renan Valieris Bueno de; Drummond, Rodrigo Duarte; Souza, Jorge Estefano de; Silva, Israel Tojal da; Souza, Sandro José de; Carraro, Dirce Maria
The majority of the hereditary triple-negative breast cancers (TNBCs) are associated with BRCA1 germline mutations. Nevertheless, the understanding of the role of BRCA1 deficiency in the TNBC tumorigenesis is poor. In this sense, we performed whole-exome sequencing of triplet samples (leucocyte, tumor, and normal-adjacent breast tissue) for 10 cases of early-onset TNBC, including 5 hereditary (with BRCA1 germline pathogenic mutation) and 5 sporadic (with no BRCA1 or BRCA2 germline pathogenic mutations), for assessing the somatic mutation repertoire. Protein-affecting somatic mutations were identified for both mammary tissues, and Ingenuity Pathway Analysis was used to investigate gene interactions. BRCA1 and RAD51C somatic promoter methylation in tumor samples was also investigated by bisulfite sequencing. Sporadic tumors had higher proportion of driver mutations (≥25% allele frequency) than BRCA1 hereditary tumors, whereas no difference was detected in the normal breast samples. Distinct gene networks were obtained from the driver genes in each group. The Cancer Genome Atlas data analysis of TNBC classified as hereditary and sporadic reinforced our findings. The data presented here indicate that in the absence of BRCA1 germline mutations, a higher number of driver mutations are required for tumor development and that different defective processes are operating in the tumorigenesis of hereditary and sporadic TNBC in young women.

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Navegando por Autor "Carraro, Dirce Maria"